Potential of hypercrosslinked microporous polymer based on carbazole networks for Pb(II) ions removal from aqueous solutions

Abstract

In this research, porous adsorbents of hypercrosslinked microporous polymer based on carbazole networks (HCP-CN) were synthesized for Pb(II) elimination from wastewaters. The results demonstrated that the extreme HCP-CN adsorbents utilization in wastewater treatment could remove more than 99.88% of Pb (II) ions. Furthermore, the two consumed adsorbents similarly indicated rapid adsorption kinetics, and it merely took a while to achieve adsorption equilibrium. These characteristics showed that HCP-CN adsorbent was an outstanding candidate for Pb(II) elimination from wastewater. Besides, the thermodynamic characteristics involving Gibbs free energy change (ΔG 0 ), entropy change (ΔS 0 ), and enthalpy change (ΔH 0 ) of the adsorption procedure were evaluated, and the results affirmed that the adsorption process was exothermic and spontaneous. In addition, response surface methodology (RSM) as a statistical investigation was used to optimize adsorption factors to obtain maximum adsorption capacity and investigate the interactive effect of parameters using central composite design (CCD). Optimum conditions obtained by RSM for maximum adsorption capacity of 26.02 mg/g are 35 °C, 40 mg/L, 11, 60 min, and 99.88 for temperature, initial concentration, pH, time, and removal percent, respectively. In the kinetic modeling study, the second-order model was selected as the best model. The values R 2 at temperatures 35 °C, 40 °C, and 55 °C are 0.997, 0.9997, and 0.998, respectively. In the isotherm modeling, Hill model with a value R 2 of 0.9766 has a superior precision compared to the other isotherm models. Also, the values of ΔH and ΔS at Pb(II) concentration of 60 mg/L are 122.622 kJ/mol and 0.463 kJ/mole K, respectively.

Porous organic polymers as a promising platform for efficient capture of heavy metal pollutants in wastewater

“…The adsorption capacity increases gradually initially with a trend of substantial alterations as the initial Pb(II) concentration rises. 150 Via the sulfonation reaction of HCPs, modified hypercrosslinked microporous "Davankov Resins" were created by Li and colleagues; these resins had improved hydrophilicity and interaction with hazardous metals for eventual elimination. Sulfonic acid-modified hypercrosslinked "Davankov resins" (SAM-HCP-DR) have been discovered to have a very strong metal ion adsorption capacity (Cu(II) 51.45 mg g −1 at 303 K, 54.82 mg g −1 at 313 K, and 57.68 mg g −1 at 323 K), which is a result of the synergistic interaction between active sites and microporous structure.…”

“…Evidently, after 35 min, the Pb( ii ) adsorption capacity reaches equilibrium, the amount of adsorption capacity becomes constant, and the passage of time has no impact on the adsorption capacity. 150 The pH of the solution has a notable impact on the adsorption of organic materials in the structure of polymers because it can affect the charge profile of the adsorbates and the functional groups of the polymers. As a result, the Pb( ii ) adsorption pattern on HCP-CN was investigated over the pH range of 2–12 with the careful addition of drops of NaOH and HCl.…”

“…The adsorption capacity increases gradually initially with a trend of substantial alterations as the initial Pb( ii ) concentration rises. 150…”

Eco-Friendly Production of Hyper-Cross-Linked Polymers Using Mechanosynthesis and Bioresources: A Critical Review

“…Based on a carbazole backbone, HCPs with surface areas and pore volumes of 689 m 2 /g and 0.54 cm 3 /g, respectively, were able to remove up to 99.88% of Pb 2+ ions from wastewater under optimal conditions (i.e., 35 °C, 40 mg/L Pb 2+ , pH 11, and adsorption time of 60 min) . In a more comprehensive study, iminodiacetic acid-functionalized HCPs (see schematics in Figure D) were used to study the selectivity in the removal of various metal ions simultaneously, which is close to a real-life scenario.…”